This invention relates to electrical connectors and more particularly to a frame-type electrical connector having molded in place terminals and used for connecting leadless integrated circuit packages to a printed circuit board.
Connectors of the class to which this invention relates employ a base in the form of a frame which has a cavity in the top surface thereof designed to receive a leadless package. A plurality of conductive elements are mounted along the periphery of the cavity and are shaped to form pressuretype electrical contacts.
The leadless package, typically in the form of a thin rectangular substrate having a plurality of conductive areas or pads spaced along its edges, is mounted within the cavity of the frame so that the conductive pads on the package face the pressure contacts. A cover is then placed over the package to the backside of the leadless package, causing the conductive pads to compress the pressure contacts. The conductive elements mounted within the frame are designed so that one end of each of these contacts projects below the bottom surface of the frame, to form a set of pin terminals designed to be soldered into mating holes in a printed circuit board. By soldering the pin terminals into the printed circuit board, electrical contact is established between the conductive pads on the leadless package and the corresponding conductors on the printed circuit board. Because of the close spacings between adjacent conductive elements, it is often desirable to shape the pin terminals so that adjacent terminals form a staggered arrangement which increases the effective distance between the terminals.
Some of the prior art connectors are designed so that individual conductive elements are inserted into the frame after the frame has been formed by means such as molding. For example, Palecek U.S. Pat. No. 3,953,101, issued Apr. 27, 1976, shows a connector designed with insertable contacts. This type of connector design requires the frame to be fabricated with means for retaining the individual contacts after they are inserted. The contacts themselves must be formed into an intricate shape both to provide the required pressure contact and to engage the retaining means in the frame, and each contact must be properly oriented when it is inserted into the frame. Generally, frame-type connectors employing insertable contacts are larger and more difficult and costly to assemble than those connectors employing molded-in contacts. In addition, insertable contacts do not possess the strength or ruggedness of molded-in contacts.
Other prior art connectors of the class to which this invention relates employ conductive elements which are molded into place along the periphery of the frame at the same time that the frame is formed. In the prior art, this type of construction, known as insert-molding, requires that each conductive element be preformed prior to assembly to form both a pressure contact and a pin terminal. Such preforming generally necessitates that conductive elements be handled one at a time and be carefully inserted into a mold in the proper orientation. Arranging the pin terminals into a staggered arrangement further complicates the performing of the contacts and results in a method of assembly that is extremely time consuming and expensive. Examples of this type of connector are shown in Cutchaw U.S. Pat. Nos. 3,904,262 and 4,063,791, issued Sept. 9, 1975 and Dec. 20, 1977, respectively.
Accordingly, it is an object of the present invention to provide a new and improved electrical connector for leadless integrated circuit packages.
It is another object of the present invention to provide a connector having molded-in conductive elements which are formed to provide pressure contacts and pin terminals after they are molded in place.
It is a further object of the present invention to provide a connector having conductive elements which may be molded in place in the form of a lead frame so that a plurality of conductive elements can be handled as a single element in the assembly of the connector.